M51-The Whirlpool Galaxy
Here's an enlarged, cropped version of M51.
Telescope: Takahashi FS-152 f/8 fluorite refractor
Zeiss II German Equatorial Mount
Santa Barbara Instrument Group ST-8E NABG CCD camera (1530 x 1020 pixels, 9 x 9mm, monochromatic, 16 bit, 13.8 x 9.2mm array)
CWF8 color filter wheel with IR-blocking red, green and blue dichroic filters
Date: Saturday, March 23, 2001
Location: Joshua Tree National Park, CA
Elevation: Approx. 4000', OAT +48F
Conditions: Windy, moderate seeing conditions.
Total exposure time: Luminance=100 minutes. RGB=20:20:30 minutes at f/8